<template>
  <div class="tags-nav">
    <div class="close-con">
      <Dropdown transfer @on-click="handleTagsOption">
        <Button size="small" type="text">
          <Icon :size="14" type="icon iconfont iconguanbianniu" />
        </Button>
        <DropdownMenu slot="list">
          <DropdownItem name="close-all">关闭所有</DropdownItem>
          <DropdownItem name="close-others">关闭其他</DropdownItem>
        </DropdownMenu>
      </Dropdown>
    </div>
    <ul
      v-show="visible"
      :style="{left: contextMenuLeft + 'px', top: contextMenuTop + 'px'}"
      class="contextmenu"
    >
      <li v-for="(item, key) of menuList" @click="handleTagsOption(key)" :key="key">{{item}}</li>
    </ul>
    <div class="btn-con left-btn">
      <Button type="text" @click="handleScroll(240)">
        <Icon :size="14" type="icon iconfont iconxiangzuojiantou" />
      </Button>
    </div>
    <div class="btn-con right-btn">
      <Button type="text" @click="handleScroll(-240)">
        <Icon :size="14" type="icon iconfont iconxiangyoujiantou" />
      </Button>
    </div>
    <div
      class="scroll-outer"
      ref="scrollOuter"
      @DOMMouseScroll="handlescroll"
      @mousewheel="handlescroll"
    >
      <div ref="scrollBody" class="scroll-body" :style="{left: tagBodyLeft + 'px'}">
        <transition-group name="taglist-moving-animation">
          <Tag
            v-for="(item, index) in list"
            ref="tagsPageOpened"
            :key="`tag-nav-${index}`"
            :name="item.name"
            :data-route-item="item"
            @on-close="handleClose(item)"
            @click.native="handleClick(item)"
            :closable="item.name !== $config.homeName"
            :color="isCurrentTag(item) ? 'primary' : 'default'"
            @contextmenu.prevent.native="contextMenu(item, $event)"
          >{{ showTitleInside(item) }}</Tag>
        </transition-group>
      </div>
    </div>
  </div>
</template>

<script>
import { showTitle, routeEqual } from '@/lib/menu-func';
import beforeClose from '@/router/before-close';
export default {
  name: 'TagsNav',
  props: {
    // 当前激活路由
    value: {
      type: Object,
      require: false
    },
    // 数据集合
    list: {
      type: Array,
      default () {
        return [];
      }
    }
  },
  data () {
    return {
      tagBodyLeft: 0,
      rightOffset: 40,
      outerPadding: 4,
      contextMenuLeft: 0,
      contextMenuTop: 0,
      visible: false,
      menuList: {
        others: '关闭其他',
        all: '关闭所有'
      }
    };
  },
  computed: {
    // 当前激活路由
    currentRouteObj () {
      const { name, params, query } = this.value;
      return { name, params, query };
    }
  },
  watch: {
    $route (to) {
      this.getTagElementByRoute(to);
    },
    visible (value) {
      if (value) {
        document.body.addEventListener('click', this.closeMenu);
      } else {
        document.body.removeEventListener('click', this.closeMenu);
      }
    }
  },
  mounted () {
    setTimeout(() => {
      this.getTagElementByRoute(this.$route);
    }, 200);
  },
  methods: {
    handlescroll (e) {
      let type = e.type;
      let delta = 0;
      if (type === 'DOMMouseScroll' || type === 'mousewheel') {
        delta = e.wheelDelta ? e.wheelDelta : -(e.detail || 0) * 40;
      }
      this.handleScroll(delta);
    },
    // 左右切换
    handleScroll (offset) {
      const outerWidth = this.$refs.scrollOuter.offsetWidth;
      const bodyWidth = this.$refs.scrollBody.offsetWidth;
      if (offset > 0) {
        this.tagBodyLeft = Math.min(0, this.tagBodyLeft + offset);
      } else {
        if (outerWidth < bodyWidth) {
          if (this.tagBodyLeft < -(bodyWidth - outerWidth)) {
            this.tagBodyLeft = this.tagBodyLeft;
          } else {
            this.tagBodyLeft = Math.max(
              this.tagBodyLeft + offset,
              outerWidth - bodyWidth - 35
            );
          }
        } else {
          this.tagBodyLeft = 0;
        }
      }
    },
    handleTagsOption (type) {
      if (type.includes('all')) {
        // 关闭所有，除了home
        let res = this.list.filter(item => item.name === this.$config.homeName);
        this.$emit('on-close', res, 'all');
      } else if (type.includes('others')) {
        // 关闭除当前页和home页的其他页
        let res = this.list.filter(
          item =>
            routeEqual(this.currentRouteObj, item) ||
            item.name === this.$config.homeName
        );
        this.$emit('on-close', res, 'others', this.currentRouteObj);
        setTimeout(() => {
          this.getTagElementByRoute(this.currentRouteObj);
        }, 100);
      }
    },
    handleClose (current) {
      if (
        current.meta &&
        current.meta.beforeCloseName &&
        current.meta.beforeCloseName in beforeClose
      ) {
        new Promise(beforeClose[current.meta.beforeCloseName]).then(close => {
          if (close) {
            this.close(current);
          }
        });
      } else {
        this.close(current);
      }
    },
    close (route) {
      let res = this.list.filter(item => !routeEqual(route, item));
      this.$emit('on-close', res, undefined, route);
    },
    // 点击标签页
    handleClick (item) {
      // 标记从tag跳转 不清除缓存和刷新页面
      if (item.params) {
        item.params.isRefresh = false;
      } else {
        item.params = { isRefresh: false };
      }
      this.$emit('input', item);
    },
    showTitleInside (item) {
      return showTitle(item, this);
    },
    isCurrentTag (item) {
      return routeEqual(this.currentRouteObj, item);
    },
    moveToView(tag) {
      const outerWidth = this.$refs.scrollOuter.offsetWidth - 50;
      const bodyWidth = this.$refs.scrollBody.offsetWidth;
      let padding = 35;
      if (bodyWidth < outerWidth) {
        this.tagBodyLeft = 0;
      } else if (tag.offsetLeft < -this.tagBodyLeft) {
        // 标签在可视区域左侧
        this.tagBodyLeft = -tag.offsetLeft + this.outerPadding + padding;
      } else if (
        tag.offsetLeft > -this.tagBodyLeft &&
        tag.offsetLeft + tag.offsetWidth < -this.tagBodyLeft + outerWidth
      ) {
        // 标签在可视区域
        this.tagBodyLeft = Math.min(
          0,
          outerWidth -
            tag.offsetWidth -
            tag.offsetLeft -
            this.outerPadding -
            padding
        );
      } else {
        // 标签在可视区域右侧
        this.tagBodyLeft = -(
          tag.offsetLeft -
          (outerWidth - this.outerPadding - tag.offsetWidth - padding)
        );
      }
    },
    getTagElementByRoute (route) {
      this.$nextTick(() => {
        this.refsTag = this.$refs.tagsPageOpened;
        this.refsTag.forEach((item, index) => {
          if (routeEqual(route, item.$attrs['data-route-item'])) {
            let tag = this.refsTag[index].$el;
            this.moveToView(tag);
          }
        });
      });
    },
    contextMenu (item, e) {
      if (item.name === this.$config.homeName) {
        return;
      }
      this.visible = true;
      const offsetLeft = this.$el.getBoundingClientRect().left;
      this.contextMenuLeft = e.clientX - offsetLeft + 10;
      this.contextMenuTop = e.clientY - 64;
    },
    closeMenu () {
      this.visible = false;
    }
  }
};
</script>

<style lang="less">
@import "./tags-nav.less";
</style>
